1. Field of the Invention
The present invention relates to a computer program product, system, and method for adapter configuration in a computing system having a storage area network.
2. Description of the Related Art
In certain computing environments, a storage area network provides data paths between multiple host systems and multiple storage control units controlling multiple storage devices e.g., a Direct Access Storage Device (DASD), Redundant Array of Independent Disks (RAID), Just a Bunch of Disks (JBOD), etc. The data paths through the storage area network typically include switches and communication links. Portions of the data paths may be formed of fiber optic or other types of cables or may be wireless, for example.
Input/output commands issued by a host are directed through the storage area network over data paths to a port of a storage control unit. A host typically connects to a data path through a host adapter which has a host port connected to a communication link of the data path. Write data issued by the host as well as read data received by the host, typically passes through the host adapter of the particular data path.
Before a host adapter becomes operational for data input and output operations, the host adapter is typically configured for operation in the particular storage area network. Configuration parameters may include the topology of the data path to which the host adapter belongs. For example, one aspect of the topology configuration may include whether the host adapter port connects directly via a communication link to a port of a storage controller, or whether there is an intermediate switch in the data path between the host and the storage controller. Other possible configuration parameters include network protocols, the transmission wavelength for fiber optic networks, and the selection of on/off procedures for turning the adapter on or off so as to minimize disruption to data transfer operations.
Each host adapter of a host typically has a specified data carrying capability. In order to improve or upgrade the data transfer rate, a host adapter may be removed and replaced with a replacement unit having a greater data carrying capability. The replacement host adapter is then configured for operation in the particular storage area network and data transfer operations may resume through the replacement host adapter.